Studio dell'effetto di Hump in un motore a solido in piccola scala con metodi di produzione di punzonatura e colaggio

L’oggetto di questo elaborato riguarda lo studio prestazionale di un Solid Rocket Motor mediante l’introduzione del fattore di “Hump”, che va a compensare il discostamento tra il profilo delle pressioni sperimentali e teoriche, cercando di legare tali variazioni a spiegazioni fisiche. In particolare andremo ad investigare, all’interno di due differenti tipologie di colata, quale sia l’effetto predominante all’interno del propellente che genera proprio tali discostamenti della pressione, e quindi della spinta, rispetto alla condizione ideale. Nell’elaborato verranno anzitutto presentate le diverse tipologie di propulsori, i loro singoli componenti, i parametri fondamentali che regolano la meccanica di questa tipologia di motori, le tipologie di grain esistenti e le loro caratteristiche. Successivamente descriveremo le BARIA (Bomb ARIAne), usate per i test del grain nella ditta AVIO s.p.a., e le tipologie di riempimento di questo motore, investigando i fenomeni fisici a cui sarà legato l’effetto di “Hump”. In seguito si descriverà il fattore di “Hump”, evidenziando, per le differenti tipologie di riempimento, i fenomeni fisici a cui sarà legato il discostamento tra le pressioni sperimentali e teoriche. Verranno poi descritti i programmi utilizzati, gli script in Matlab prodotti, al fine di ottenere le mappe relative all’orientazione ed alla concentrazione delle particelle, da introdurre nel simulatore. Infine verranno esposti i risultati ottenuti e confrontati con i dati sperimentali forniti dalla ditta AVIO s.p.a., le conclusioni e gli sviluppi futuri.

Adsorption Calorimetry for Energy Conversion Technologies: Applications in Organic Photovoltaics, Catalysis, and Atomic Layer Deposition

Thesis (Ph.D.)--University of Washington, 2016-07

Lasten vetoomus pysyvän rauhan puolesta. Hiroshimalaisten lasten ja nuorten muistelmat atomipommi-iskun jälkeiseltä ajalta ja iskun vaikutus heidän käsityksiinsä tulevaisuudesta vuonna 1951

Tässä pro gradu -tutkielmassa perehdyin siihen, miten hiroshimalaiset lapset ja nuoret kuvasivat muistelmissaan Hiroshiman atomipommi-iskun jälkeistä aikaa, ja miten iskun nähtiin vaikuttaneen heidän käsityksiinsä tulevaisuudesta. Lähestyin aihetta muistitietotutkimuksen metodin kautta. Alkuperäisaineistonani käytin Arata Osadan kokoamaan muistelmateosta Children of the A-Bomb: Testament of the Boys and Girls of Hiroshima, joka pitää sisällään 105 lasten ja nuorten kirjoittamaa muistelmaa atomipommi-iskun jälkeisestä ajasta vuonna 1951. Ajallisesti tutkielmani rajautuu lasten kuvaamaan kuuteen vuoteen atomipommi-iskusta kirjoitushetkeen, sekä muistelmissa kuvattuun tulevaisuuteen. Pääpaino on kuitenkin vuodessa 1951. Teos edustaa japanilaista toisen maailmansodan jälkeistä sodan vastaista kirjallisuutta, jonka motiivina on rauhanaatteen edistäminen. Muistelmateoksesta on nähtävissä, kuinka lapset tulkitsevat iskun jälkeistä nykyisyyttä oman selviytymisensä kautta. Monet nuorimmista lapsista kuvasivat kokemaansa kiitollisuuden tunnetta auttajaa kohtaan, kun taas vanhempien lasten muistelmissa kuvataan enemmän itse avunantoa. Vanhemmat lapset olivat useammin poissa kotoa ja vailla vanhempiensa turvaa, joten he joutuivat tekemään itsenäisempiä päätöksiä. Selviytyminen herätti niin kiitollisuutta, mutta myös ahdistusta ja tarvetta perustella omaa selviytymistään. Muistelmista on myös havaittavissa japanilaisen historiantulkinnan murrosvaihe. Sodan jälkeinen miehityspolitiikka opetti japanilaisia syyttämään imperialistista hallitusta sodasta, ja toisaalta kielsi Yhdysvaltojen ja atomipommien käytön kritisoinnin. Kuitenkin sensuurin loputtua myös Yhdysvaltoja kohtaan alkoi esiintymään kritiikkiä. Lasten muistelmissa onkin nähtävissä vaihtelevia tapoja kommentoida atomipommi-iskun syitä ja seurauksia. Menneisyyden ja nykyisyyden tulkinnan ohella muistelmissa on nähtävissä myös lasten ja nuorten käsityksiä tulevaisuudesta. Tulevaisuuden käsityksiin vaikutti erityisesti kylmän sodan epävakaa konteksti, joka nosti esiin uuden sodan pelon. Lisäksi muistelmissa oli myös nähtävissä normaalin arjen pelkoja, kuten kiusaamista. Toisaalta moni koki päässeensä yli menneisyyden traumasta ja pyrki omalla toiminnallaan vaikuttamaan tulevaisuuteen rauhaa edistävästi.

Thermodynamic modeling and microcalorimetry of nanostructured materials for capacitive thermal management of electronics

Transient power dissipation profiles in handheld electronic devices alternate between high and low power states depending on usage. Capacitive thermal management based on phase change materials potentially offers a fan-less thermal management for such transient profiles. However, such capacitive management becomes feasible only if there is a significant enhancement in the enthalpy change per unit volume of the phase change material since existing bulk materials such as paraffin fall short of requirements. In this thesis I propose novel nanostructured thin-film materials that can potentially exhibit significantly enhanced volumetric enthalpy change. Using fundamental thermodynamics of phase transition, calculations regarding the enhancement resulting from superheating in such thin film systems is conducted. Furthermore design of a microfabricated calorimeter to measure such enhancements is explained in detail. This work advances the state-of-art of phase change materials for capacitive cooling of handheld devices.

Conflictos de interés, riesgo y presiones que enfrenta a diario el periodista en La Troncal y sus sectores aledaños

El presente trabajo Riesgos y presiones del Periodista en La Troncales de trascendental importancia en el sentido que en nuestra ciudad, no existe un periodismo de vanguardia. El periodista en La Troncal, tiene un campo de acción que está empezando, está todo por hacerse; sin embargo, no deja de ser menos notorio los riesgos y presiones. Por lo tanto, no deja de ser peligrosa esta actividad para quien la ejerce. Una muestra del riesgo latente, constituye los casos que presentamos aquí en esta tesina. Así por ejemplo, el hecho de Byron Baldeón, fue un suceso que causó conmoción a nivel internacional por la crueldad con la que se actuó. Este asesinato sigue todavía en investigación, pues hasta la vez no se ha llegado a encontrar a los culpables. Así mismo, el caso de Carlos Bejarano Ramos que pasó el susto de su vida y quien estuvo a punto de morir con toda su familia se salvaron por un milagro, la bomba que fue lanzada a su morada no estalló. En conclusión, este tema que presentamos en la tesina es interesante porque el periodista en este sector se desempeña en un ambiente de mucho riesgo y lo que es peor sin apoyo de su patrono y de ninguna asociación, pues laboran algunos hasta sin seguro social lo cual hace más dramática la situación en que se hallan la mayoría de los aficionados y profesionales del periodismo tanto como de La Troncal y El Triunfo.

Fire protection durability of intumescent coatings after accelerated aging

The most common method of achieve the required fire resistance is by the use of passive fire protection systems, being intumescent coatings the fire protection material frequently used. These are usually considered thin film coatings as they are applied with a dry film thickness (DFT) between 0.3-3 [mm]. The required DFT is obtained by experimental fire resistance tests performed to assess the contribution of this reactive fire protection material to the steel member fire resistance. This tests are done after dry coating and a short time period of atmospheric conditioning, at constant temperature and humidity. As the coatings formulation is mainly made from polymeric basis compounds, it is expected that the environmental factors, such temperature, humidity and UV radiation (UVA and UVB) significantly affect the intumescent coating fire protection performance and its durability. This work presents a research study about the effects of aging on the fire protection performance of intumescent coatings. A commercial water based coating is submitted to an accelerated aging cycle, using a QUV Accelerated Weathering Tester. This tests aim to simulate 10 years of the coating natural aging. The coating durability is tested comparing the fire protection of small steel samples submitted to a radiant heat flux exposure from a cone calorimeter. In total, 28 tests were performed on intumescent coating protected steel specimens, of which 14 specimens were tested before the hydrothermal aging test and other 14 after accelerated aging. The experimental tests results of the steel temperature evolution shows that increasing the intumescent dry coating film thickness, the fire resistance time increases. After the accelerated aging cycles, the coating lose their ability to expand, resulting in an increase of the steel temperature of approximately 200 [ºC], compared to the samples without aging.

L1 track finding for a time multiplexed trigger

At the HL-LHC, proton bunches will cross each other every 25. ns, producing an average of 140 pp-collisions per bunch crossing. To operate in such an environment, the CMS experiment will need a L1 hardware trigger able to identify interesting events within a latency of 12.5. μs. The future L1 trigger will make use also of data coming from the silicon tracker to control the trigger rate. The architecture that will be used in future to process tracker data is still under discussion. One interesting proposal makes use of the Time Multiplexed Trigger concept, already implemented in the CMS calorimeter trigger for the Phase I trigger upgrade. The proposed track finding algorithm is based on the Hough Transform method. The algorithm has been tested using simulated pp-collision data. Results show a very good tracking efficiency. The algorithm will be demonstrated in hardware in the coming months using the MP7, which is a μTCA board with a powerful FPGA capable of handling data rates approaching 1. Tb/s.

Investigation of capacitive discharge heating of metallic glasses

In recent years, the discovery of bulk metallic glasses with exceptional properties has generated much interest. One of their most intriguing features is their capacity for viscous flow above the glass transition temperature. This characteristic allows metallic glasses to be formed like plastics at modest temperatures. However, crystallization of supercooled metallic liquids in the best bulk metallic glass-formers is much more rapid than in most polymers and silicate glass-forming liquids. The short times to crystallization impairs experimentation on and processing of supercooled glass-forming metallic liquids. A technique to rapidly and uniformly heat metallic glasses at rates of 10⁵ to 10⁶ kelvin per second is presented. A capacitive discharge is used to ohmically heat metallic glasses to temperatures in the super cooled liquid region in millisecond time-scales. By heating samples rapidly, the most time-consuming step in experiments on supercooled metallic liquids is reduced orders of magnitude in length. This allows for experimentation on and processing of metallic liquids in temperature ranges that were previously inaccessible because of crystallization.

A variety of forming techniques, including injection molding and forging, were coupled with capacitive discharge heating to produce near net-shaped metallic glass parts. In addition, a new forming technique, which combines a magnetic field with the heating current to produce a forming force, was developed. Viscosities were measured in previously inaccessible temperature ranges using parallel plate rheometry combined with capacitive discharge heating. Lastly, a rapid pulse calorimeter was developed with this technique to investigate the thermophysical behavior of metallic glasses at these rapid heating rates.

Síntese do Poli (ácido láctico) por policondensação direta utilizando um planejamento fatorial

The environmental impact caused by the disposal of non-biodegradable polymer packaging on the environment, as well as the high price and scarcity of oil, caused increase of searches in the area of biodegradable polymers from renewable resources were developed. The poly (lactic acid) (PLA) is a promising polymer in the market, with a large availability of raw material for the production of its monomer, as well as good processability. The aimed of this study was synthesis PLA by direct polycondesation of lactic acid, using the tool of experimental design (DOE) (central composite rotatable design (CCRD)) to optimize the conditions of synthesis. The polymer obtained was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), viscosimetric analysis, differential scanning calorimeter (DSC) and size exclusion chromatography (SEC). The results confirmed the formation of a poly (lactic acid) semicrystalline in the syntheses performed. Through the central composite rotatable design was possible to optimize the crystallization temperature (Tc) and crystallinity degree (Xc). The crystallization temperature maximum was found for percentage of catalyst around the central point (0,3 (%W)) and values of time ranging from the central point (6h) to the upper level (+1) (8h). The crystallization temperature maximum was found for the total synthesis time of 4h (-1) and percentage of catalyst 0,1(W%) (-1). The results of size exclusion chromatography (SEC) showed higher molecular weights to 0,3 (W%) percent of catalyst and total time synthesis of 3,2h

Detonating the research plan: exploding the supervisory process

Bomb making is dangerous work. And not just because what you’re creating can blow up in your face. Even as you type in your search terms – how to make a bomb – you wonder who is watching, what algorithm might throw you up into the light of surveillance and trigger the knock at the door. (McKnight, 2014, p. 1)AbstractSo begins Lucinda’s PhD. In this dialogic paper of interwoven stories we employ a critical auto-ethnographic approach to explode moments of our lives and work together as we worked through the “research plan” at the heart of the supervision timeline. Lucinda’s thesis highlights the way curriculum emerges from the struggles of ideological becoming (Bakhtin 1981) as she and a group of teachers, sought to produce and perform both individual gendered identities (Butler 1997, 2007) and plans for the identities of student subjects, while negotiating subject positions made available to girls and women in broader social contexts. The link between the personal and political is created by a methodology combining narrative inquiry and discourse analysis as a heteroglossic (Bakhtin, 1981) text. In this paper we detonate the research plan developed in the first months of the PhD timeline as Jo responds to Lucinda’s narratives with her own, and we share jointly written narratives that try to capture some key moments of the process. We rework our own stories of the supervised and the supervisor through the competing discourses of our work and lives.

Measurement and data transmission validity of a multi-biosensor system for real-time remote exercise monitoring among cardiac patients

Background: Remote telemonitoring holds great potential to augment management of patients with coronary heart disease (CHD) and atrial fibrillation (AF) by enabling regular physiological monitoring during physical activity. Remote physiological monitoring may improve home and community exercise-based cardiac rehabilitation (exCR) programs and could improve assessment of the impact and management of pharmacological interventions for heart rate control in individuals with AF.

Objective: Our aim was to evaluate the measurement validity and data transmission reliability of a remote telemonitoring system comprising a wireless multi-parameter physiological sensor, custom mobile app, and middleware platform, among individuals in sinus rhythm and AF.

Methods: Participants in sinus rhythm and with AF undertook simulated daily activities, low, moderate, and/or high intensity exercise. Remote monitoring system heart rate and respiratory rate were compared to reference measures (12-lead ECG and indirect calorimeter). Wireless data transmission loss was calculated between the sensor, mobile app, and remote Internet server.

Results: Median heart rate (-0.30 to 1.10 b∙min-1) and respiratory rate (-1.25 to 0.39 br∙min-1) measurement biases were small, yet statistically significant (all P≤.003) due to the large number of observations. Measurement reliability was generally excellent (rho=.87-.97, all P<.001; intraclass correlation coefficient [ICC]=.94-.98, all P<.001; coefficient of variation [CV]=2.24-7.94%), although respiratory rate measurement reliability was poor among AF participants (rho=.43, P<.001; ICC=.55, P<.001; CV=16.61%). Data loss was minimal (<5%) when all system components were active; however, instability of the network hosting the remote data capture server resulted in data loss at the remote Internet server during some trials.

Conclusions: System validity was sufficient for remote monitoring of heart and respiratory rates across a range of exercise intensities. Remote exercise monitoring has potential to augment current exCR and heart rate control management approaches by enabling the provision of individually tailored care to individuals outside traditional clinical environments.

Dynamic virtual workspace for teleoperation of heterogeneous robots in non-deterministic environments

Robots are ever increasing in a variety of different workplaces providing an array of benefits such alternative solutions to traditional human labor. While developing fully autonomous robots is the ultimate goal in many robotic applications the reality is that there still exist many situationswere robots require some level of teleoperation in order to achieve assigned goals especially when deployed in non-deterministic environments. For instance teleoperation is commonly used in areas such as search and rescue, bomb disposal and exploration of inaccessible or harsh terrain. This is due to a range of factors such as the lack of ability for robots to quickly and reliably navigate unknown environments or provide high-level decision making especially intime critical tasks. To provide an adequate solution for such situations human-in-the-loop control is required. When developing human-in-the-loop control it is important to take advantage of the complimentary skill-sets that both humans and robots share. For example robots can performrapid calculations, provide accurate measurements through hardware such as sensors and store large amounts of data while humans provide experience, intuition, risk management and complex decision making capabilities. Shared autonomy is the concept of building robotic systems that take advantage of these complementary skills-sets to provide a robust an efficient robotic solution. While the requirement of human-in-the-loop control exists Human Machine Interaction (HMI) remains an important research topic especially the area of User Interface (UI) design.In order to provide operators with an effective teleoperation system it is important that the interface is intuitive and dynamic while also achieving a high level of immersion. Recent advancements in virtual and augmented reality hardware is giving rise to innovative HMI systems. Interactive hardware such as Microsoft Kinect, leap motion, Oculus Rift, Samsung Gear VR and even CAVE Automatic Virtual Environments [1] are providing vast improvements over traditional user interface designs such as the experimental web browser JanusVR [2]. This combined with the introduction of standardized robot frameworks such as ROS and Webots [3] that now support a large number of different robots provides an opportunity to develop a universal UI for teleoperation control to improve operator efficiency while reducing teleoperation training.This research introduces the concept of a dynamic virtual workspace for teleoperation of heterogeneous robots in non-deterministic environments that require human-in-the-loop control. The system first identifies the connected robots through the use kinematic information then determines its network capabilities such as latency and bandwidth. Given the robot type and network capabilities the system can then provide the operator with available teleoperation modes such as pick and place control or waypoint navigation while also allowing them to manipulate the virtual workspace layout to provide information from onboard camera’s or sensors.

A new biocompatible ionic liquid as an antiwear additive for biodegradable lubricants

A new biocompatible ionic liquid P1444DPP (IL1) was investigated as an antiwear additive and compared against Amine Phosphate (AP), one of the commonly used conventional antiwear additives in various biodegradable base stocks. In general, such base stocks (vegetable oil and synthetic esters) are being used for preparing biodegradable industrial lubricants. To further check its efficacy, the results were also compared with one of the ionic liquid P66614DPP (IL2) which has better performance as a lubricant, but is less biocompatible. IL1 showed excellent antiwear performance on pin-on-disc tribometer, when blended in biodegradable base stocks. The steel balls after the pin-on-disc test were analyzed using SEM-EDS technique. The oxidation stability of IL1 was studied by Pressure Differential Scanning Calorimeter (PDSC) and compared with the behavior of AP after incorporating optimized dosage of antioxidant additives in the biodegradable base stock.

Lord of the ring: redressing the ‘White Oliphant’

 The doctoral work is divided into two parts: an exegesis dealing analytically with the idea of writing nonfiction works about scientists and a creative nonfiction work on the Australian scientist Sir Mark Oliphant encompassing also the practice of science, its culture, its politics and its intellectual arguments.

'Give back the human': poetic collaboration and hibakusha poems

Testimonies are viewed as essential for recording the experience of atomic warfare. However, hibakusha Keiko Ogura expresses the need for something more than recording and translating these testimonies. She highlights the need for an understanding of the hibakusha experience through a form of virtual collaboration with hibakusha and their stories. Ogura states that this is best achieved via ‘literature, art and poetry’ (Ogura 2015: n.pag.).This paper discusses why and how we speak about the atomic bomb and argues that virtual collaboration with hibakusha, by writing poetry based on their experiences and publishing it online, encourages empathy and keeps the experience alive for future generations. This paper uses Brandon Shimoda’s curated issue—entitled ‘Hiroshima/Nagasaki’—of Evening Will Come, a monthly online journal of poetics, as a case study.